The Comptroller encourages all taxpayers to support Texas businesses while saving money on tax-free purchases of most clothing, footwear, school supplies and backpacks (sold for less than $100) during the annual Tax-Free weekend. Qualifying items can be purchased tax free from a Texas store or from an online or catalog seller doing business in Texas. In most cases, you do not need to give the seller an exemption certificate to buy qualifying items tax free. For more information visit comptroller. Texas.gov.
https://comptroller.texas.gov/taxes/publications/98-490/